Drilling hole in foam rubber?

I'm trying to make a special gasket out high density foam rubber. Actually I'm using a kid's 4oz practice hockey puck as the blank. It's 1" thick and I need to make a 1" hole in it's center. Does anyone know of type of bit or other type of cutter that would make a clean cut. The common bits and step bits just rip it up.

Reply to
Martin
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Have you tried using a 1" hole saw in reverse? Should work fine.

R
Reply to
RicodJour

Foam does not drill easily. It can be cut using a smaller diameter end mill in a drill press and moving the foam around it to make the hole.

You may want to try a brad point or forstner bit as it will cut the sides better than a twist drill. You can also try sandwiching the rubber between two pieces of wood and drill through the whole thing. That will work well for thin materials, but I'm not sure about 1" thick.

Reply to
Edwin Pawlowski

I have carved holes in poly foam with a small wire brush on a Mototool to make replacement pads for headphones. It's not a precise operation. Also, there's a lot of electrostatically charged dust flying around so I did it outdoors. Don't know how well it would work on rubber foam.

SJF

Reply to
SJF

Hot wire might work. Look it up on google. A high-pressure water cutter is used for similar foams in fabricating plants.

Mike

Reply to
Michael Daly

You need to freeze it before drilling. With a puck you probably need to freeze it with dry ice (handle the puck with thick gloves when you drill it).

Reply to
George E. Cawthon

I haven't seen one of these practice pucks so I have no idea how stiff the foam is but:

  1. The first thing that comes to mind is one of those Greenlee chassis punches. It was a die for cutting large holes in an aluminum chassis. I see they're still sold:
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    your local TV/electronics shop has one you can borrow for 2 minutes. Brand new it might do the job.
  2. I also think the above poster might be right about the reversed hole saw. You might also be able to compress the puck between two sheets of ply and hole saw through the sandwich.
  3. Grind the teeth off an old 1" hold saw to make a cylindrical knife. Use a drill press as a mini press to cut straight thru the foam. No rotation or perhaps a back and forth stroke. Actually I remember doing this with my drill press using some thin wall tubing on some HD polyu. Richard
Reply to
spudnuty

I

No need for the plywood. It's the same idea as reversing the saw blade in a circular saw when cutting vinyl siding. It works fine. It's simple.

R
Reply to
RicodJour

Yes, if the OP wants good advice, he should give more details. There are various densities that are or might be called high density. Most of us have never seen a hockey puck up close, much less a kid's practice hockey puck. As opposed to a kid's actual hockey puck.

I do know that parents try to avoid having their kids' teeth knocked out, and most would want it as soft as could possibly work. Maybe it's the foam version of a wiffle ball.

Describe it in terms we can understand.

Remove NOPSAM to email me. Please let me know if you have posted also.

Reply to
mm

Don't know for sure if this would work, but:

Put a 1" hole saw bit on a drill press or press punch and *push* it through without drilling.

Reply to
Randy Day

I think that reversed hole saw might work if sufficiently lubricated say with soapy water; this foam has an awful drag. Problem is I don't have that kind of equipment here. But it did put me in mind of another hole cutter: the cork borer that used to be used in laboratories; basically a simple die cutter that was worked by hand. I could probably make one from sharpened

3/4" copper pipe which would give me an OD of about 7/8", close enough for my purpose.
Reply to
Martin

and I

BTDT, for foam for camera and equipment cases. Find a tin can or spray can of the right diameter, or even a piece of pipe, and cut it off square. Sharpen the edge, and use that as a knife to cut the foam. A lathe helps for pipe, that is why thin tin cans are easier. Use a rod inside the can, and roll it on a flat surface, to make it round again after you cut it.

aem sends....

Reply to
ameijers

I think that reversed hole saw might work if sufficiently lubricated say with soapy water; this foam has an awful drag. Problem is I don't have that kind of equipment here. But it did put me in mind of another hole cutter: the cork borer that used to be used in laboratories; basically a simple die cutter that was worked by hand. I could probably make one from sharpened

3/4" copper pipe which would give me an OD of about 7/8", close enough for my purpose.
Reply to
Martin

You don't have a drill and a hole saw...

You don't need to lubricate foam rubber. The hole saw in reverse will work, but feel free to make it as complicated of a process as you'd like.

R
Reply to
RicodJour

Maybe a dumb idea. Soak in water and freeze it, then drill with a spade bit while the water is frozen.

Reply to
Jeff

About the easiest thing to do is take a one inch pipe and sharpen one end . Press the pipe through the puck or pound it through using a rubber mallet and a piece of wood. You could even drill a hole into the wooden block to hold the pipe steady. The sharpened edge of the pipe will glide through the puck easily.

Reply to
newfysnapshot

This might work:

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Reply to
Norminn

Reply to
barbarow

Re the cork borer. That may be do the job. I remembered those from way back and indicated earlier in this thread that a I would probably be looking at a homemade version. Don't recall a 1" size in the sets I used. Do you know of a source? I've since tried the reversed hole saw that was suggested, but lubricated or not it tore up the foam. I need a smooth inside wall. The sharp edge like on the borer might do it. It'll need a gentle touch.

Reply to
Martin

I've used the reversed hole saw > Probably your best bet would be a "cork Borer" which is a set of hollow

Thank you! I wasn't familiar with the cork boring tools. I have one of the cork borer sharpeners and I never knew what it was used for! The cork borer is a simple idea and I'm sure it would work well in the foam rubber, but I did a quick search and I didn't see any in a 1" size. I think it'll have to be a homemade item.

R
Reply to
RicodJour

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